:root {
  --bg-top: #07131f;
  --bg-bottom: #030712;
  --panel: rgba(7, 16, 31, 0.94);
  --chip: rgba(15, 23, 42, 0.78);
  --line: rgba(148, 163, 184, 0.18);
  --text: #f8fafc;
  --muted: #bfd4ec;
  --accent: #38bdf8;
  --accent-strong: #0ea5e9;
  --accent-alt: #f59e0b;
  --danger: #fb7185;
  --success: #34d399;
  --shadow: 0 24px 72px rgba(2, 8, 23, 0.42);
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 12%, rgba(56, 189, 248, 0.2), transparent 30%),
    radial-gradient(circle at 88% 16%, rgba(245, 158, 11, 0.16), transparent 24%),
    linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 100%);
  display: flex;
  justify-content: center;
  padding: 16px;
  padding-top: max(16px, env(safe-area-inset-top));
  padding-right: max(16px, env(safe-area-inset-right));
  padding-bottom: max(16px, env(safe-area-inset-bottom));
  padding-left: max(16px, env(safe-area-inset-left));
}

.app {
  width: min(980px, 100%);
  background: linear-gradient(180deg, rgba(10, 18, 33, 0.96), rgba(6, 12, 24, 0.96));
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 28px;
  padding: clamp(16px, 2vw, 24px);
  box-shadow: var(--shadow);
}

.hero {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.hero-copy {
  display: grid;
  gap: 8px;
}

.eyebrow {
  margin: 0;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

h1 {
  margin: 0;
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  line-height: 1;
}

.intro {
  margin: 0;
  max-width: 46ch;
  color: var(--muted);
  font-weight: 600;
}

.hero-actions,
.button-cluster,
.tower-picker {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.hud {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 16px;
}

.stat-card {
  display: grid;
  gap: 6px;
  padding: 14px 16px;
  border-radius: 20px;
  background: var(--chip);
  border: 1px solid var(--line);
}

.stat-label {
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.stat-card strong {
  font-size: clamp(1.15rem, 2.2vw, 1.5rem);
}

.board-card {
  display: grid;
  gap: 12px;
  padding: 14px;
  border-radius: 24px;
  background:
    radial-gradient(circle at top, rgba(56, 189, 248, 0.1), transparent 45%),
    linear-gradient(180deg, rgba(12, 20, 36, 0.96), rgba(5, 10, 22, 0.96));
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.board-wrap {
  margin-inline: auto;
  padding: 12px;
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(10, 16, 30, 0.92), rgba(3, 7, 18, 0.92));
  border: 1px solid rgba(148, 163, 184, 0.16);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.board-wrap.compact {
  width: min(100%, 520px);
}

.grid-board {
  display: grid;
  gap: 10px;
  aspect-ratio: 1 / 1;
  padding: 10px;
  border-radius: 18px;
  background: rgba(6, 11, 22, 0.94);
  border: 1px solid var(--line);
}

.tile-board {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.tile {
  display: grid;
  place-items: center;
  aspect-ratio: 1 / 1;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  font-size: clamp(1rem, 4vw, 1.8rem);
  font-weight: 800;
  transition: transform 140ms ease, background 140ms ease, color 140ms ease;
  user-select: none;
}

button {
  border: 0;
  border-radius: 999px;
  padding: 0.9rem 1.2rem;
  font: inherit;
  font-weight: 800;
  letter-spacing: 0.01em;
  cursor: pointer;
  color: #06222a;
  background: linear-gradient(180deg, #67e8f9, var(--accent));
  box-shadow: 0 12px 28px rgba(14, 165, 233, 0.22);
  transition: transform 160ms ease, box-shadow 160ms ease, opacity 160ms ease;
  touch-action: manipulation;
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 32px rgba(14, 165, 233, 0.26);
}

button:active {
  transform: translateY(1px) scale(0.99);
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.ghost {
  color: var(--text);
  background: linear-gradient(180deg, rgba(21, 32, 56, 0.96), rgba(10, 17, 31, 0.96));
  border: 1px solid rgba(148, 163, 184, 0.18);
  box-shadow: none;
}

.action-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.control-pad {
  display: grid;
  grid-template-columns: repeat(3, minmax(64px, 88px));
  grid-template-areas:
    ". up ."
    "left down right";
  justify-content: center;
  gap: 10px;
}

.control {
  display: grid;
  place-items: center;
  aspect-ratio: 1 / 1;
  padding: 0;
  border-radius: 22px;
  color: var(--text);
  background: linear-gradient(180deg, rgba(19, 33, 57, 0.96), rgba(9, 17, 30, 0.96));
  border: 1px solid rgba(148, 163, 184, 0.18);
  box-shadow: 0 12px 28px rgba(2, 8, 23, 0.26);
  font-size: 1.3rem;
}

.up {
  grid-area: up;
}

.left {
  grid-area: left;
}

.down {
  grid-area: down;
}

.right {
  grid-area: right;
}

.legend {
  margin: 0;
  max-width: 44ch;
  color: var(--muted);
  font-weight: 700;
  line-height: 1.5;
}

#msg {
  margin: 0;
  min-height: 1.4em;
  text-align: center;
  color: var(--muted);
  font-weight: 700;
}

@media (max-width: 820px) {
  .hud {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-actions {
    width: 100%;
  }

  .hero-actions button {
    flex: 1 1 0;
  }

  .action-row {
    flex-direction: column;
    align-items: stretch;
  }

  .legend {
    max-width: none;
    text-align: center;
  }
}

@media (max-width: 520px) {
  body {
    padding: 12px;
    padding-top: max(12px, env(safe-area-inset-top));
    padding-right: max(12px, env(safe-area-inset-right));
    padding-bottom: max(12px, env(safe-area-inset-bottom));
    padding-left: max(12px, env(safe-area-inset-left));
  }

  .app {
    padding: 14px;
    border-radius: 22px;
  }

  .board-card {
    padding: 10px;
  }

  .board-wrap {
    padding: 10px;
  }

  .grid-board {
    gap: 8px;
    padding: 8px;
  }

  .tile {
    border-radius: 14px;
  }

  .control-pad {
    grid-template-columns: repeat(3, minmax(58px, 76px));
  }

  .control {
    border-radius: 18px;
  }
}

@media (max-width: 390px) {
  .stat-card {
    padding: 12px;
  }

  .tile {
    font-size: 0.96rem;
  }

  .legend {
    font-size: 0.92rem;
  }
}